Early male touch fastener products were generally woven materials, with hooks formed by cut filament loops. More recently, arrays of very small touch fastener elements have been formed by molding the fastener elements, or at least the stems of the elements, of resin forming an interconnecting sheet of material.
In most applications, male fastener elements are designed to releasably engage with a mating female fastener component carrying a field of loops or fibers. To engage the loops, the male fastener elements must penetrate the field of fibers at least until the tips of the engaging fastener element heads have sufficiently extended beyond some of the fibers, such that the fibers can be engaged within the crooks of the heads. Thus, enhancing penetration tends to lead to longer, more slender hooks.
Subsequent to engagement, retention of an engaged fiber or loop depends, at least for loads within the ability of the loop to resist breakage, upon resistance of the hook to distention and/or breakage. Distention is the opening of the crook under load of an engaged loop. For high cycle life applications, breakage of either both loops and hooks is undesirable. Thus, the ability of the fastening to resist peel loads in such applications is generally limited by the ability of the hook to resist distention.
Unfortunately, for many applications increasing the rigidity of hooks designed for maximum loop penetration, to increase their peel resistance, is either undesirable or impractical. For example, many applications require a gentle ‘feel’ of the male fastener element array against the skin.
Further improvements in the overall design of male fastener elements, particularly those formed or molded of resin and arranged in large numbers upon a surface for engaging loops or fibers, are desired. Preferably, such improved fastener elements will be readily and efficiently manufacturable without great advances in manufacturing methods.